WO 92/20496 (U.S. Pat. No. 5,484,181) shows a gripping mechanism of the generic type, comprising at least one movable gripper finger, guided as a coupler of a six-link guiding mechanism with a central sliding joint. The central sliding joint is in the form of a pneumatic cylinder having a continuous piston rod and serves as a common drive element for all gripper fingers of the same gripping mechanism. The gripper finger of this gripping mechanism moves on an exact straight line normal to the longitudinal axis A of the gripper. The parallel gripping range, i.e. the gripping stroke, of this gripping mechanism is small in relation to current requirements on a flexible gripper.
German Democratic Republic Patent DD 2 65 354 A1, in FIG. 2, shows a gripping mechanism for handling devices having two gripper jaws 7. Each gripper jaw 7 is guided by means of a ten-link mechanism on an exact straight line. The coupling point G of the mechanism, also guided in an exact straight line and in the same direction, serves as a drive point for the movement of the gripper jaw and as a synchronization point of the movement of the two gripper jaws. The coupling point G of the mechanism is driven by a spindle drive 11 and 12. The mechanism thus makes itself redundant since it is possible to directly drive the gripper jaws with the straight-line spindle drive like a parallel vise.